In collaboration with a Senior Investigator in the Axon Guidance and Neural Connectivity Section, NINDS, and with his post-doctoral fellow, and with members of the Biomedical Imaging Research Services Section of the Office of Intramural Research, CIT, we are studying the mechanisms that guide neurons axons to their ultimate targets. In particular, we are analyzing experiments that record the the growth of a neuron in the wing disc extracted from Drosophlia larvae. During these experiments, we monitor the dynamics of a cytoskeletal protein, actin, at sub-micrometer resolution for periods up to an 1.5 hours in the growing axon as it senses it way through the muscle tissue of the disc. We are also examining the effects on the axon growth dynamics by mutations in a kinase that modulates the actin activity. An article is in preparation for submission to peer review. Furthermore, we are studying new techniques to increase the imaging sampling rate cellular cytoskeletal dynamics while reducing the damage to the cells being observed. In collaboration with a principal investigator and staff clinician in Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute of Alcohol Abuse and Alcoholism, and with a staff scientist in the Mathematical and Statistical Laboratory, Office of Intramural Research, CIT, we are studying the factors that influence patients with alcohol use disorder (AUD) to seek treatment. This study involves analysis of hundreds of environmental, physiological, and psychiatric factors collected for each patient. A manuscript describing an alternative decision tree for predicting the propensity of AUD patients to seek or not seek treatment (and that could be use by the AUD treatment providers in the field) has been submitted for peer-review. In addition, we are applying methods from information theory to explore the spectrum of these factors in the AUD population. In collaboration with a consortium of investigators consisting of (1) a principal investigator and staff clinician in Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute of Alcohol Abuse and Alcoholism, (2) a principal investigator and staff clinician in Cognitive Neuroscience and Psychopharmacology Section, Neuroimaging Research Branch, National Institute on Drug Abuse, and (3) a staff scientist in the Mathematical and Statistical Laboratory, Office of Intramural Research, CIT, we are investigating differences in the decision making process between addicts and non-addicts. In particular, we are comparing cigarette smokers, cocaine users, and a set of non-smoking, non-addicted controls to each other. We study their decision making process using a trust game approach in which players (the subjects) decide whether or not to trust each other or a randomized computer algorithm in dispensing financial gains or penalties. Our preliminary results suggest that cocaine users respond differently from non-using controls and cigarette smokers, especially in the initial stages of the game. From 2012 to 2017, the LI worked with a principal investigator in Section on Neuronal Connectivity, NICHD, (Chi-hon Lee) on statistical and topological analysis of retinal neurons growth in Drosophila. In FY 2018, Dr. Lee left the NIH to become the director of the Institute of Cellular and Organismic Biology, Academia Sinica, in Taipai, Taiwan. The LI and Dr. Lee, along with (1) a staff scientist in NICHD, and (2) members of the Biomedical Imaging Research Services Section of the Division of Computational Bioscience, CIT, are now finishing up their long-term collaboration. Two papers are being prepared for peer-review.